Exemplary embodiments of the present invention relate to a parallel intra prediction method for video data, and more particularly, to a parallel intra prediction method for video data capable of separating reference pixels into pixels predicted from the reference pixels during an encoding and decoding process for video data to perform intra prediction in parallel.
A demand for high-definition moving picture services has been increased with the development of various multimedia devices and the generalization of digital multimedia broadcasting services and the overall traffic of a network has been increased with the expansion of high-definition moving picture services. For this reason, attempts to develop a video codec for effectively encoding or decoding high-resolution video contents have been variously conducted.
Generally, in order to effectively compress video data, the encoding for video data is performed by a series of processes of dividing an original image into a plurality of blocks, predicting video data at locations of each block, and transforming and quantizing a difference value between original data and predicted data, and the like.
As described above, as a method for generating prediction image during an encoding process for video data, intra prediction and inter prediction have been proposed.
The intra prediction, which is a method for generating prediction signals from signals around a block to be encoded, removes spatial redundancy for video data present within a single frame to realize data compression.
On the other hand, the inter prediction indicates locations of the prediction signals by a motion vector based on motion estimation in a reference image to remove temporal redundancy for video data present between different frames.
FIG. 1 is a diagram illustrating an intra prediction mode and a prediction direction for a H.264/AVC 4×4 block.
Describing the intra prediction of the H.264/AVC encoder in accordance with the related art, the intra prediction may be performed in a 4×4, 8×8, and 16×16 pixel block unit and the 4×4 and 8×8 blocks use nine prediction modes and the 16×16 block uses four prediction modes.
Referring to FIG. 2 in which the intra prediction mode and the prediction direction of the 4×4 block are illustrated, the 4×4 pixel block shaded in each prediction mode is an encoding target block and the prediction signals of each pixel within the encoding target block are generated from the reference pixels represented by A, B, . . . , M neighbor thereto.
As an example of generating the prediction signals, in case of a vertical prediction mode represented by mode 0 of FIG. 1, A, B, C, and D pixels each are copied to pixels within the encoding target block on an arrow.
FIG. 2 is a diagram illustrating a prediction signal generation order for performing intra prediction encoding.
Generally, the intra prediction generates the prediction signals from the pixels around the encoding target block, such that inter-block data dependency is present during the encoding and decoding process.
For example, when a macro block 310 illustrated in FIG. 2 is subjected to the intra prediction encoding at a size of 4×4 block 320 based on a H.264/AVC compression standard, sixteen 4×4 blocks represented by No. 1, 2, . . . , 16 are present.
Here, in case of Nos. 2 and 3 blocks, the prediction signals for all the prediction modes can be generated after a prediction signal of No. 1 block is generated and in the case of No. 4 block, the prediction signals for all the prediction modes can be generated after the prediction signals of Nos. 2 and 3 blocks are generated. That is, it is difficult to rapidly perform the intra prediction due to the inter-block data dependency.
As the related art, there is KR Patent Laid-Open No. 2001-0045132 (Jun. 5, 2001, Title of the Invention: Intra Frame Encoding Method).
The above-mentioned technical configuration is a background art for helping understanding of the present invention and does not mean related arts well known in a technical field to which the present invention pertains.